Manufacture of sheets or plates of manganese steel.



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UNITED STATES PATENT @FFTCE.

WINFIELD S. POTTER, OF NEW YORK, N. Y.

MANUFACTURE OF SHEETS OR PLATES OF MANGANESE STEEL.

No Drawing.

To all whom it may concern:

Be it known that I, \VINFIELD S. POTTER, a citizen of the United States, residing at the Apthorp Aparti'nents, at the corner of Broadway and Seventy-eighth street, in the borough of Manhattan, in the city, county, and State of Xew York, have invented certain new and useful Improvements in the Manufacture of Sheets or Plates of Manganese Steel; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In an application for Letters Patent of the United States, filed by me under date of November 4, 1011, Serial No. 058,425, I have described the n'ianufacture of sheets or plates from manganese steel I billets or blanks (having a percentage of manganese above per cent. and usually containing about 12 per cent), the final product of the operation being of a substantially uniform, finegrained condition throughout, and having the desired stiffness or ductility appropriate to the use for which it is intended.

In my application referred to, the method described involves first heating the inaliganese steel billet or sheet bar until it is brought into a uniform and ductile condition throughout. appropriate to the rolling operation. To this end, the necessary plasticity is imparted to the billet or sheet bar, by raising it to a temperature which, for the production of the best results. will usually be above the melting point of the eutectic alloy, that is, above 1125 C. (say 1125 C. to 1225 C., according to the ductility required for rolling), but which, in some instances, may be as low as 1000 C., provided the subsequent reduction from the billet to the sheet or plate in a single heat is not considerable.

In accordance with the present invention, the blank in the condition of ductility to which it has been brought by the heating operation referred to, may then be rolled at a temperature which, in the finishing stage of the rolling may be below 800 C., as. for example, a temperature as low as 500 C.

The product will then require a reheating or annealing operation to obtain a suitablytough product for most purposes, inasmuch as rolling at temperatures below 800 (1, and particularly below 720 C., leaves the metal in a very stifi' and brittle condition,

Specification of Letters Patent.

Patented Feb. 20, 1912.

Application filed January 10, 1912. Serial No. 670,377.

similar to that produced by the cold rolling or wire-drawing of mild steel. If, for example, the sheet or plate is finished at a temperature of say, 700 C. or lower, it is reheated for the purpose of bringing it back to a suitable condition of toughness and ductility. For the purposes of this reheating of sheets finished at these low tempera tures, the reheating furnace will usually be maintained at a temperature of about 975 C. to 1075 C., and the sheet or plate will be he )t in the furnace for such time only as is nec ssary to bring it to the furnace temp rature and to effect the resolution of slich carbids as have separatedout during the cooling of the steel.

In case the minimum stiffness consistent with a tough and coherent condition of the to any temperature either above or below 800 (1, and even down to say 500 0., and then reheated to a temperature sufficient to give it the necessary ductility for rolling to finished form, and, if worked to finished dimensions at a temperature which, in the finishing stage, is below 800 (I. (say 700 C. or lower), it should then be brought to the suitable condition of toughness and ductility by reheating itto a temperature such that any carbids which may have separated are restored to solution by heating to say from 975 C. to 1075 (3.; or, if rapidly cooled and rapidly reheated after the final rolling, the sheet may be annealed and'rendered ductile by reheating to any temperature between about 800 C. and 1075 C. In any case, the sheet or plate is retained in the furnace for such time only as is necessary for it to assume throughout the furnace temperature, whereupon the metal will be regrained, or restored to uniformity by the re-' uilforded by the previous heating end working, the sheet or plate may be held iu the furnace for a short time after it has assumed the furnace temperature, care being taken that it shall not attain for any considerable time, a tcm 'ierature much, if any, more 'l'llftll about 1025 U. and that it shall not remain long at any equalized tempereture above aboutQi'li u.

Having thus described my lIlVQI).'ClOIl,\Vl12llL I claim is:

'l. llhc method of making" sheets or plates of manganese steel, which comprises heatinp a billet or blank of manganese steel until in a uniform and ductile condition tin-oughout, rollinq' and thhieby Working at temperatures which, in the finishing stage, are below S00 reheating until any separated carbide have been taken into solution; and quenching; substantially as described.

The method of making sheets or plates of manganese steel, which comprises heating it billet or blank of manganese steel until in uniform and ductile condition throughout, rolling and thereby working temperatures which, in the finishing stage, are below 800" U, reheating at temperatures between 975 (fl. and M75 U; and quenching; substaniy us described.

'3. The method. of making sheets or plates of mangi anese steel, which comprises heating a billet or blank of manganese steel until in a unifori'n and ductile condition throughout, rolling and tl'icreby Working, with inter-- m :liute reheating, the Working being" effected at temperatures which, in the finishing etc are below 800 (1., reheating; to restore duct. ity; and quenching; substantially as described.

4;. The me hod of Lltlklfig' sheets or plates rated carbids have been taken into solution and continuing the reheating for such time only that the plate is suitably annealed or toughened; and quenching; substantially as described.

5. In the manufacture of sheets or plates of manganese steel, by rolling a billet or blank of manganese steel previously heated until in a uniform and ductile condition throughout, the method of restoring to solution any carbide which may have separated in the rolled metal which consists in reheating the rolled metal to temperatures between 975 C. and 107590.; and quenching; substantially as described.

6. In the manufacture of sheets or. plates of manganese steel, by rolling abillet or blank of manganese steel previously hated until in a uniform and ductile condition throughout, the method of restoring to solution any carbids which may have separated in the rolled metal and annealing or toughoiling the metal, which consists in reheating the rolled metal to temperatures between 975 C. and 1075 C. for such time only that the sheet or plateis suitably annealed or toughened; and quenching; substentiallyas described.

In testimony whereof I effix my signature, in presence of two Witnesses.

VVINFIELD S. PUTTER.

lVitnesses: I

JOHN C. PENNIE,

MINERVA LoBnL. 

